Mine Gases and Ventilation: Textbook for Students of Mining, Mining Engineers and Candidates Preparing for Mining Examinations Designed for Working Out the Various Problems that Arise in the Practice of Coal Mining, as They Relate to the Safe and Effecient Operation of MinesMcGraw-Hill, 1920 - 433 páginas |
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Resultados 1-5 de 58
Página xii
... split- ting Theoretical considerations in splitting - Practical problem . PRACTICAL VENTILATION CHAPTER VII Conducting air currents , air bridges - General plan of mine- Distribution of air in the mine - Splitting air currents - Sys ...
... split- ting Theoretical considerations in splitting - Practical problem . PRACTICAL VENTILATION CHAPTER VII Conducting air currents , air bridges - General plan of mine- Distribution of air in the mine - Splitting air currents - Sys ...
Página 194
... splits A , B and C , instead of writing Xa + Xo + Xc . In a complex circulation , consisting of a main airway and two or more splits , it is often necessary to indicate the gen- eral split potentials by Xo , Xao , Xoo , etc. , and the ...
... splits A , B and C , instead of writing Xa + Xo + Xc . In a complex circulation , consisting of a main airway and two or more splits , it is often necessary to indicate the gen- eral split potentials by Xo , Xao , Xoo , etc. , and the ...
Página 200
... split , a definite value that enables a correct comparison to be made between them , and the proper type of ventilator and system of ventilation to be chosen . Potential of Airway . - Calculate the potential of an airway 6 X 10 ft ...
... split , a definite value that enables a correct comparison to be made between them , and the proper type of ventilator and system of ventilation to be chosen . Potential of Airway . - Calculate the potential of an airway 6 X 10 ft ...
Página 204
... splits or currents . Calling the number of equal splits n , the area of passage ( p . 211 ) , in splitting an air current is na , and the formula for the potential can be written : Split potential , X = na V ks Since the rubbing surface ...
... splits or currents . Calling the number of equal splits n , the area of passage ( p . 211 ) , in splitting an air current is na , and the formula for the potential can be written : Split potential , X = na V ks Since the rubbing surface ...
Página 205
... splits , 120,000 ÷ 360 333 sq . ft . But the area of the entries being each 60 sq . ft . , the number of splits required to give this area of passage and thus keep the velocity of the air currents in the splits within the specified ...
... splits , 120,000 ÷ 360 333 sq . ft . But the area of the entries being each 60 sq . ft . , the number of splits required to give this area of passage and thus keep the velocity of the air currents in the splits within the specified ...
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Mine Gases and Ventilation: Textbook for Students of Mining, Mining ... James Thom Beard Sin vista previa disponible - 2018 |
Términos y frases comunes
absorbed acetylene air column air current airway antilog atmosphere atoms battery breathing bag bulb Bureau of Mines burning calculated carbide carbide lamp carbon dioxide carbon monoxide cent chemical chimney circulation coal combustion constant corresponding Cosine Sine Cosine Cotang Tang Cotang cubic cylinder Davy lamp density downcast dust equal explosive firedamp formula gaseous gases gauze given horsepower hydrogen ignition inches increase inflammable intake liquid logarithm long ton mantissa mercury methane minute mixture molecular molecules nitrogen oxygen passing percentage of gas potential values pounds power potential pressure potential produced quantity of air ratio reaction rubbing surface safety lamps saturated saturated vapor pressure seam sectional area shaft shown Sine Cosine Sine specific gravity square substance Tang Cotang Tang temperature tion tube unit pressure upcast valve vapor pressure varies velocity ventilating pressure volume of air water gage water vapor wearer weight
Pasajes populares
Página 401 - Minutes = 1 Hour 24 Hours = 1 Day 7 Days = 1 Week 28 Days = 1 Lunar Month...
Página 29 - Al . . . .Sb ....A ....As ....Ba . ...Bi . ...B . ...Br . . . .Cd . . . .Cs . . . .Ca ....C . . . .Ce . . . .Cl . ...Cr ....Co . ...Cb . . . .Cu...
Página 399 - Apothecaries' weight 20 grains = 1 scruple 3 scruples = 1 dram = 60 grains 8 drams = 1 ounce = 24 scruples...
Página 152 - ... skilled in such work, and all parts that require sterilizing shall be readily accessible for this purpose. (c) All parts of the apparatus subject to or liable to be subjected to pressures in excess of 5 pounds per square inch shall be...
Página 42 - Law states that the rates of diffusion of gases are inversely proportional to the square roots of their densities. Or...
Página 156 - Test 15 is made to determine the maximum length of time that the apparatus will supply the needs of the wearer when in a quiescent state. The wearer will remain as far as possible in a sitting posture throughout the test and perform no work. He will be allowed to manipulate the devices controlling the compressed-oxygen or compressedair supply to conserve such compressedoxygen or compressed-air supply to the greatest advantage.
Página 102 - AC, it follows, ex cequali, that as AM is to AC so is the time along AM to the time along AC. THEOREM IV, PROPOSITION IV The times of descent along planes of the same length but of different inclinations are to each other in the inverse ratio of the square roots of their heights From a single point B draw the planes BA and BC, having the same length but different inclinations; let AE and CD be horizontal lines drawn to meet the perpendicular BD; and...
Página 55 - ... the weight of an equal volume of air at the same temperature and pressure.
Página 150 - Permissibility tests will not be made unless the unit has been completely developed and is a form that can be marketed. (f ) The results of the tests shall be regarded as confidential by all present at the tests and shall not be made public in any way before the shot-firing unit is formally approved by the Bureau of Mines.
Página 152 - A self-contained breathing apparatus in which the expired atmosphere is recirculated shall be provided with a release valve that is operated manually or automatically and is placed at some point in the circulatory system of the apparatus. The function of this valve shall be...